How serious of an issue is Kyrie Irving's constant knee soreness?

The news trickling out on Kyrie Irving’s sore left knee has seemingly been encouraging from a Celtics perspective over the past few days.

Brad Stevens said on Wednesday night that the imaging “looked great” on Irving’s left knee and he would travel with the team on their two-game road trip to Orlando and New Orleans this weekend after missing Wednesday's game against the Wizards.

Irving had surgery to repair a fractured left kneecap during the 2015 NBA Finals and Danny Ainge admitted in an appearance on Toucher and Rich Thursday that the soreness in the same knee is something the All-Star point guard would have to deal with throughout the rest of this season and his career. The team was aware of that reality when they traded for the 25-year-old back in August.

"There was a lot of discussion (at the time)," Ainge told Toucher & Rich on 98.5 The Sports Hub. "And that was a big part of it going forward too was Kyrie had the injury. So we knew there would be maintenance issues, but his long-term prognosis is good. He's going to have some maintenance issues here and there. We knew coming into this year that he probably wasn't going to be an 82-game guy. He was going to be a 72-, 75-game guy in order to keep him fresh for the playoffs. And that’s what it's been. And we're just extra cautious. We have the good fortune of being extra cautious right now. And we want him fresh and healthy. And we think that he will be, come playoff time."

Ainge also admitted Irving may need to have some minor knee surgery at some point in the next summer or two to address the soreness issue. In an attempt to shed some more light on the situation and the challenges that Irving faces this year and beyond, I caught up with Boston Sports Journal’s medical expert Dr. Jessica Flynn for her insight on Irving’s situation and how much C’s fans should be concerned about his status.

Q: What do you attribute Irving’s constant knee soreness from? Is it simply a normal issue for any player that has the type of surgery he did?

Dr. Flynn: I think all of his (knee) issues have been from the same problem. The same problem is overuse to the mechanism that allows you to straighten your knee out. Basically, your quad muscles turn into what's called the patellar tendon and that attaches to the shin bone. The kneecap sits in that, right? So a lot of basketball players get a problem with that. It's called jumper's knee for a reason. He's been dealing with that for many years. He's struggled since college with that problem.

I think the patellar fracture he had (in Cleveland) was actually part of that same issue. It was sort of a stress injury to the kneecap that finally broke through in one game. They had said it was more of an acute injury, but I think (and a lot of doctors) think that it was a stress fracture. It's all part of the same process and it doesn't surprise me that he's still dealing with patellar tendonitis.

That's really painful to play through and really hard to get rid of. I've treated pro soccer players who have to rest for a whole year in their 20s. They had to take a whole year off and they didn't get better. It is one of those tough things and there are a lot of things that we do in medicine to try to treat it — stem cell injections, surgery to debride the tendon, rest, therapy — but it's just one of those really tough things to treat and get rid of completely. I agree with Danny Ainge that he'll probably have to manage it his whole career.

Q: The Celtics seem to have the two seed wrapped up in the East, but the team obviously wants Irving to stay in shape ahead of the playoffs. What do you think is the balancing act there where he takes a week or two off and then plays a little bit after that? Limited minutes?

Dr. Flynn: He didn't sound psyched about limited minutes on Sunday night, so I don't know if he'll go for that. I definitely think a period of rest more than just a couple of days. They'll work his minutes back in slowly is what I expect. I think there is no reason not to preserve him at this point.

Q: Is this a situation where it can be feeling good or bad depending on the day and you hope it doesn't get really bad with the pain as the playoffs go along?

Dr. Flynn: It really is a pain issue, but in the back of his mind, he had a patellar fracture from this, right? There are some injuries where I tell athletes that you can push through this. I rarely say that, but this is one of those things where he saw the consequences of that most likely and is probably is why he had a patellar fracture and had to have surgery. At this point, it doesn't make sense to let him get to that point where he feels like he's really pushing through stuff. I think he'll be fine through the playoffs as long as you're not seeing him limping after every game, then I think it's reasonable. It's something that can be managed.

Q: Any worries about his health long-term with his injury? Will Celtics doctors have to think harder about giving a green light to a long-term deal for him? Or is something he should be able to manage?

Dr. Flynn: I think it's definitely something that will come into the equation. The other question is whether he will consider surgery this offseason. If it's a major issue for him where he's losing time and playing through more pain than any of us really know about, if his performance is affected, the question is whether he will consider having surgery this offseason to debride it and address the hardware in the kneecap (if he has some in there), if that's causing the issue. Those are things he could theoretically address this offseason. It's definitely something to certainly think about and monitor the symptoms to see which trajectory it's taking. Is it getting better or worse each season? I certainly don't think it's career ending or anything like that. I worried much more about the Isaiah Thomas hip injury than this one.